| 摘要 |
<p>Prepn. of d-2-(6-methoxynapth-2-yl)propionic acid comprises (a) condensation of the corresp. racemic propanal with d-oxalic acid alpha-phenylethylamide hydrazide in anhydrous benzene in presence of iodine; (b) resolving the diastereoisomeric hydrazones by crystallizing from dioxan to give the pure d-d isomer; (c) hydrolysing the d.-d-isomer with 20% H2SO4 to give the d-propanal and (d) oxidising the d-propanal with sodium hypochlorite soln. in presence of sulphamic acid. The l-I isomer may be recovered tom l-d-III in the fioxan mother liquors, racemized and treated as above. Simple process, economic because the l-isomer of the propanal can easily be racemized to give the d-acid. Product is an antiinflammatory, analgesic, antipyretic agent. Typically, pure d-d-III hydrazone, crystallised from dioxan, was hydrolysed with 20% H2SO4 at reflux for 15 min to give almost 100% yield of d-propanal. Oxidation with Na-OCl in water and benzene in presence of sulphamic acid gave 75% of d-2-(6-methoxynaphth-2-yl)propionic acid.</p> |
